Device for aligning a data carrier plate with respect to a data transmission head

ABSTRACT

The invention relates to a device for aligning a data carrier plate and its drive ( 11 ) with respect to a data transmission head in a data transmission device, in which data are read from or written into the data carrier plate by means of light rays, which data carrier plate is arranged with its drive on a carrier ( 10 ) which can be aligned with respect to the data transmission head and for this purpose comprises adjustment locations ( 12, 13, 14 ) which cooperate with adjustment members ( 15, 17 ) and thus define adjustment distances, wherein one of the adjustment members ( 15 ) acts on an associated adjustment location ( 12 ) on the carrier ( 10 ) so as to modify its adjustment, and the contact rods ( 2 ) comprise adjustment locations ( 13, 14 ) formed by surface deformations in contact regions ( 8 ), which adjustment locations ( 13, 14 ) cooperate in an adjustment-modifying manner with adjustment members ( 17 ) contacting said adjustment locations ( 13, 14 ).

The invention relates to a device for aligning a data carrier plate andits drive with respect to a data transmission head in a datatransmission device, in which data are read from or written into thedata carrier plate by means of light rays, which data carrier plate isarranged with its drive on a carrier which can be aligned with respectto the data transmission head and for this purpose comprises adjustmentlocations which cooperate with adjustment members and thus defineadjustment distances. The device is particularly suitable for devices ofplanar construction, the so-termed slim construction, such as, forexample, navigation devices in motor vehicles or handheld devices.

It is known to arrange the drive of a digital data carrier plate on aplanar carrier which can be adjusted with respect to a digital datatransmission head. Three adjustment locations are provided on thecarrier plate. Two of these adjustment locations are formed byelevations which must be manufactured to a very high accuracy so as todefine a desired adjustment position with high accuracy. The adjustmentlocations abut against the surfaces of contact rods in the operationalposition, which rods are provided on the base plate of the player. Thevertical positions of the adjustment locations are defined by thecontact rods; they cannot be corrected anymore after being definedduring mounting. The third adjustment location cooperates with asetscrew. A rotation of the setscrew changes its adjustment positionwith respect to the associated adjustment location.

It was found that this adjustment of the carrier plate is unsatisfactoryowing to tolerances. There is no possibility for a full adjustmentcorrection afterwards.

It is an object of the invention to improve the adjustment possibilityof the carrier plate with the data carrier plate supported thereby andthe plate drive with respect to the data transmission head. This objectis achieved in a device having the characterizing features of the firstclaim. If the contact rods also allow an adjustment, all adjustmentpoints have become modifiable. This leads to a substantially moreaccurate alignment of the carrier with respect to the data transmissionhead. A known three-point adjustment is preferred.

In a further embodiment of the invention, one of the adjustment membersis a threaded bolt whose position can be adjusted. The threaded boltaccommodated in the base plate acts on the one of the three adjustmentlocations for vertical adjustment.

In a yet further embodiment of the invention, the contact rods compriseeccentric deformations in their contact regions for the adjustmentlocations, which deformations have an adjustment-modifying effect whenthe rotational position of the respective rod is changed.

A preferred embodiment of the eccentric deformations is formed byeccentric depressions in the regions of the adjustment locations. Whenthe contact rods are rotated, the adjustment locations will follow thesurfaces of the depressions. This renders it possible to adjust thedistances between the contact rods and the adjustment locations on thecarrier plate.

The depressions in the contact rods can be manufactured with littleextra expenditure; they achieve the above object in an elegant,effective, and simple manner.

The invention will be explained in more detail below with reference tothe drawing, in which:

FIG. 1 shows two contact rods and a carrier of a drive of a data carrierplate, which scans adjustment locations set for various vertical levelsby means of reference pins, in plan view,

FIG. 2 shows the arrangement of FIG. 1 in side elevation, and

FIG. 3 is a cross-sectional view of one of the contact rods taken on theline III-III, where an eccentric depression region is clearly to beobserved.

The device according to the invention is particularly suitable forappliances of planar construction, the so-called slim construction, suchas, for example, navigation devices in motor vehicles or handhelddevices. In such a device, contact rods 2 are provided mutually parallelon a base plate 1 shown in FIG. 2. These contact rods 2 lie on supports3 of the base plate 1. Clamps 4 retain the contact rods 2 on the baseplate 1. The distance between the contact rods 2 is determined byreference pins 5. Axial regions 2 a are provided within which the rodsurfaces 6 have been modified by means of depressions 7. The surfaces 8of the depressions 7 are eccentric. The purpose of this eccentricitywill be explained further below.

A planar carrier 10 supports a drive motor 11. This serves to drive adata carrier plate which is not shown. The data carrier plate is to beaccurately aligned with respect to a data transmission head (not shown)such that the focused light can be directed very accurately onto writesurfaces (not shown) of the data carrier plate. The planar carrier 10 ismade adjustable so as to achieve this.

Three adjustment locations 12, 13, 14 are provided in the comers of atriangle. The adjustment location 12 cooperates with a tilting screw 15acting as an adjustment member, which is adjustable in the direction ofa double arrow 16 on the carrier 10 towards or away from the latter soas to adjust the vertical position of the adjustment location 12. Spacerpins 17 acting as adjustment members are provided in the adjustmentlocations 13 and 14, abutting against the surfaces 8 of the eccentricdepressions 7.

When the rods 2 are rotated in the direction of a double arrow 2 b,different surface portions of the eccentric depressions 7 will come tolie below the spacer pins 17. Said pins are lifted and lowered therebyin the direction of a double arrow 18, taking the adjustment locations13 and 14 along with them.

The carrier 10 of the drive motor 11 and the fastenings of the datacarrier plate connected thereto can thus be exactly adjusted withrespect to the data transmission head, i.e. also at any time aftermounting. This is of major importance for subsequent fine tuning.

1. A device for aligning a data carrier plate and its drive (11) withrespect to a data transmission head in a data transmission device, inwhich data are read from or written into the data carrier plate by meansof light rays, which data carrier plate is arranged with its drive on acarrier (10) which can be aligned with respect to the data transmissionhead and for this purpose comprises adjustment locations (12, 13, 14)which cooperate with adjustment members (15, 17) and thus defineadjustment distances, wherein one of the adjustment members (15) acts onan associated adjustment location (12) on the carrier (10) so as tomodify its adjustment, and the contact rods (2) comprise adjustmentlocations (13, 14) formed by surface deformations in contact regions(8), which adjustment locations (13, 14) cooperate in anadjustment-modifying manner with adjustment members (17) contacting saidadjustment locations (13, 14).
 2. A device as claimed in claim 1,characterized by a three-point support with three adjustment locations(12, 13, 14).
 3. A device as claimed in claim 1, characterized in thatone of the adjustment members (15) is a threaded bolt whose position canbe modified.
 4. A device as claimed in claim 1, characterized in thatthe contact rods (2) comprise eccentric deformations (7) in theircontact regions (8) for the adjustment locations (13, 14), whichdeformations (7) have an adjustment-modifying effect when the rotationalposition of the respective rod (2) is changed.
 5. A device as claimed inclaim 4, characterized in that the eccentric deformations (7) are formedby eccentric depressions in the contact regions of the adjustmentlocations (13, 14).